@include base(solution) {
    $part-padding: (
        default: 40px 0,
        md: 80px 0,
        lg: 100px 0,
    );
    $part-header-font-size: (
        default: 24px,
        md: 32px
    );
    $part-header-margin-bottom: (
        default: 1em
    );
    $part-title-font-size: (
        default: 16px,
        md: 24px
    );
    $part-intro-font-size: (
        default: 14px
    );
    $challenge-name-size: (
        default: 14px,
        lg: 20px
    );
    $main-header-height: (
        default: 100px,
        md: 145px
    );
    $main-margin: (
        default: 20px 0,
        lg: 80px 0
    );
    $main-item-title: (
        default: 18px,
        sm: 20px,
        lg: 24px
    );
    $main-item-a: (
        default: 14px,
        md: 16px
    );
    $main-window-padding: (
        default: 20px,
        md: 50px
    );
    
    &-part {
        color: #444;
        @include responsive($part-padding, padding);
        
        .header {
            text-align: center;
            font-weight: bold;
            @include responsive($part-header-font-size, font-size);
            @include responsive($part-header-margin-bottom, margin-bottom);
            
            &::before {
                content: '\20';
                display: block;
                width: 30px;
                height: 5px;
                background: url('~assets/images/line-small.png') no-repeat center;
                background-size: cover;
                margin: 0 auto 8px;
            }
        }
        
        .title {
            text-align: center;
            font-weight: bold;
            margin-bottom: .5em;
            @include responsive($part-title-font-size, font-size);
        }
        
        .intro {
            @include responsive($part-intro-font-size, font-size);
            
            p {
                text-align: justify;
                padding: 1em 0;
                line-height: 1.6;
            }
        }
    }
    
    &-challenge {
        background: url('~assets/images/bg-5.jpg') no-repeat center;
        background-size: cover;
        height: auto;
        padding: 35px 0;
        
        .header {
            text-align: center;
            font-weight: bold;
            @include responsive($part-header-font-size, font-size);
            @include responsive($part-header-margin-bottom, margin-bottom);
            
            &::before {
                content: '\20';
                display: block;
                width: 30px;
                height: 5px;
                background: url('~assets/images/line-small.png') no-repeat center;
                background-size: cover;
                margin: 0 auto 8px;
            }
        }
        
        .icon {
            width: 72px;
            height: 72px;
            border-radius: 100%;
            font-size: 0;
            background-color: rgba(21, 124, 231, .06);
            margin: 0 auto;
            position: relative;

            &:after {
                $--margin: 10px;
                content: '\20';
                display: block;
                position: absolute;
                top: $--margin;
                right: $--margin;
                bottom: $--margin;
                left: $--margin;
                background-color: rgba(21, 124, 231, .06);
                border-radius: 100%;
                transform-origin: center;
                @include transition(transform 400ms ease);
            }

            img {
                width: 100%;
                position: relative;
                z-index: 1;
            }
        }

        .name {
            margin-top: 10px;
            font-weight: bold;
            color: #444;
            @include responsive($challenge-name-size, font-size);
        }
        
        .challenge {
            display: flex;
            flex-wrap: wrap;
        }
        
        .item {
            text-decoration: none;
            width: 50%;
            text-align: center;
            margin-top: 30px;
            display: block;
        }
    }
    
    &-main {
        border-radius: 3px;
        box-shadow: 0 2px 20px rgba(0, 0, 0, .08);
        @include responsive($main-margin, margin);
        
        &__header {
            background: url('~assets/images/bg-6.png') no-repeat center;
            background-size: cover;
            border-top-left-radius: 3px;
            border-top-right-radius: 3px;
            display: flex;
            justify-content: center;
            align-items: center;
            @include responsive($main-header-height, height);
        
            .header {
                text-align: center;
                font-weight: bold;
                color: #fff;
                @include responsive($part-header-font-size, font-size);

                &::before {
                    content: '\20';
                    display: block;
                    width: 30px;
                    height: 5px;
                    background-color: #fff;
                    margin: 0 auto 8px;
                }
            }
        }
        
        &__body {
            background-color: #fff;
            border-bottom-left-radius: 3px;
            border-bottom-right-radius: 3px;
            
            .item {
                padding: 1.5em;
                
                .title {
                    color: #444;
                    font-weight: bold;
                    margin-bottom: 12px;
                    @include responsive($main-item-title, font-size);
                    
                    &::after {
                        content: '\20';
                        display: block;
                        width: 23px;
                        height: 3px;
                        background: url('~assets/images/line-small.png') no-repeat center;
                        background-size: cover;
                        margin-top: 5px;
                    }
                }
                
                .list {
                    line-height: 2;
                    
                    a {
                        display: inline-block;
                        margin-right: 10px;
                        text-decoration: none;
                        color: #444;
                        @include responsive($main-item-a, font-size);
                        
                        &:hover {
                            color: #3a85f9;
                        }
                    }
                }
            }
        }
    }
    
    &-window {
        @include responsive($main-window-padding, padding-bottom);
        
        .header {
            text-align: center;
            font-weight: bold;
            @include responsive($part-header-font-size, font-size);
            @include responsive($part-header-margin-bottom, margin-bottom);
            
            &::before {
                content: '\20';
                display: block;
                width: 30px;
                height: 5px;
                background: url('~assets/images/line-small.png') no-repeat center;
                background-size: cover;
                margin: 0 auto 8px;
            }
        }
    }
}

@include adaptive(sm) {
    @include base(solution) {
        &-part {
            .header {
                text-align: left;
                &::before {
                    margin-left: 0;
                }
            }
            
            .title {
                text-align: left;
            }
        }
        
        &-challenge {
            .item {
                width: 25%;
                margin-top: 0;
            }
        }
        
        &-main {
            &__body {
                overflow: hidden;
                
                .item {
                    float: left;
                    width: 50%;
                    height: 135px;
                    border-bottom: 1px solid #eaeaea;
                    
                    &:nth-child(even) {
                        border-left: 1px solid #eaeaea;
                    }
                }
            }
        }
    }
}

@include adaptive(md) {
    @include base(solution) {
        &-part {
            background: url('~assets/images/bg-4.png') no-repeat right center;
            background-size: auto 350px;
            padding-right: 390px;
        }
        
        &-challenge {
            .header {
                text-align: left;
                padding-top: 20px;
                
                &::before {
                    margin-left: 0;
                }
            }
            
            .title {
                text-align: left;
            }
            
            .challenge {
                display: block;
                text-align: right;
            }
            
            .item {
                display: inline-block;
                width: auto;
                margin-left: 80px;
            }
        }
        
        &-main {
            &__body {
                .item {
                    width: 25%;
                    height: 210px;
                    border-left: 1px solid #eaeaea;
                    border-bottom: 0;
                    
                    &:first-child {
                        border-left: 0;
                    }
                    
                    .list {
                        a {
                            margin-right: 15px;
                        }
                    }
                }
            }
        }
    }
}

@include adaptive(lg) {
    @include base(solution) {
        &-challenge {
            .item {
                margin-left: 100px;
            }
        }
    }
}